Hollow sections, or tubes, capable of being displaced in one another in a telescopic manner may be used as height-adjustable support legs or corner posts with collapsible tents, as described in European patent EP-A-0'514'574. Octagonal telescopic tubes with grooves for accommodating keder sections are described in WO 02/08549. This type of tube is made of lightweight metal, preferably aluminum, with only the outer surfaces being anodized. The inner and outer tubes of the corner posts are provided with corresponding bores at predefined positions, and may be locked to one another in desired relative positions by way of fixation pins which are impinged by spring force. A well known type of a fixation pin manufactured as a single piece from a strip of sheet metal according to U.S. Pat. No. 6,089,247 is shown in FIG. 1. The free rear end of the spring steel sheet comes to bear on the inner side of the metal section, and, since the aluminum section is not anodized on the inside, this may lead to wear and slivers (chips). The worn-away aluminum particles may accumulate and settle between the inner and outer telescopic tube, and compromise the ability of the tubes to be displaced in one another. In the worst scenario, a mutual jamming, or blocking, of the tubes may occur.
The known fixation pins are not very stable with regard to their position and tend to “disappear” in the section when they have been completely pressed into the section. One cause of this originates from the V-shaped spring body which does not press the pin upwards in an exactly perpendicular manner, but also exerts components of forces which act in a transverse manner. It is important to users of the fixation pins that the pins are stable with regard to position. Stability of fixation pins has been achieved in the current state of the art, as shown in FIG. 1, wherein the rear end of the spring is welded or soldered on the hollow section in order to prevent the dislocation. This may only be accomplished, however, with fixation pins having hollow section at the end. If the fixation pins have to be positioned further to the inside in the section, then they may only be fixed in this manner with a considerable expense. Also, during the insertion of the known fixation pins impinged by spring force into the telescopic tubes, the pins can easily tilt, or jam, and furthermore scratch the inner wall. The jamming renders the assembly at different locations considerably more difficult.
It is therefore desirable to provide a fixation pin that solves the aforementioned problems.